As access to medical care continues to improve people are living longer. Yet, aging-associated diseases, such as calcium disorders, still present a barrier to increases in life expectancy and to improvements in the quality of life. Irregularities in calcium metabolism or homeostasis are linked to several pathological disorders, including osteoporosis, osteitis deformans, arthritis and osteolytic bone metastasis.
It is estimated that 10 million Americans have established osteoporosis and another 34 million have osteopenia, or low bone mass, accounting for approximately 1.5 million fractures annually. Bone metastases have also been shown to pose a major issue in many frequently occurring malignancies. Hypercalcemia, resulting from bone resorption, is an important complication of malignancy, causing most distressful symptoms, such as severe pain, spontaneous fractures, and in some cases metabolic coma and death. Moreover, studies have shown that neoplastic cell-induced osteolysis may determine the localization and provide growth enhancement of the tumor. (Mundy et. al., 1987, Bone, 8 supp. 1:S9-5; Rubin et al., 1985, Calcium in Biological Systems, Plenum Press, NY; both of which are hereby incorporated by reference).